US891366A - Internal-combustion engine. - Google Patents

Description

PATBNTBD JUNE 23,- 1908.

J. H. PIERCE. INTERNAL COMBUSTION ENGINE.

APPLIOATION FILED NOV. 8, 1906.-

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QFEEQEQ TENTEENAL'CGMBUSTHEN ENGIQNE Michigan, have invented certain new and useful improvements in internalsComh'nstion Engines; and .i do hereby declare the following lobe a hill, clear, and exact de scription of the in'vei'ilion, such as will enable others skilled in the art to which it appertains to make and use the same.

My im ention relates to internal comhustion engines of the two-cycle type, rear com- )ression, ileretoiore, many attempts have lmen made to improve engines of this type, in order that lliey may compare l lLYU'l'nlJly this so in those two-c cle en ines wherein the .l is

idle stroke of the piston operates to draw the succeeding charge into a closed crank case past an atmospherieally actuated valve, hut

no one, so l ar as I am nix arc, has devised any means for perfecting the operatimi oi this inlet valve. Hitherto such inlet valve has fluttered or chatter-ed on its seat when the engine is at high speed, owing to the extreme rapidity of reciprocation ol the piston, and while an operative motor was attained, it was of comparatively low speed. At high speed, he. motor was not wholly satisfactory, owing to the Fact that the valve was neither on nor oil its seat a any one time, and a conserelieve this objection, and. by so doing to the piston on i supward limit of movement raise the elliciency of the twoseyele motor. ltn'ill' also be noted that in a three-port engine the duct forming the passage from the two sides of the piston to charge the cylinder, makes an additional space to be filled hy air when the piston is nearly to the end of its stroke.

sage is uncovered, it causes a ire=;luction of presaire in tho crank-case by reason oiits requiring filling, and the reduction in speed. of the piston causes no additional opening of the suction valve. To insure a greater sup ply of air to the crank-Jase just before the piston gets to its imper limit. of movement than at any other time, I have a pipe leading from the inlet pipe, behind its suction valve, to the cylinder, and its end entering the cylinder is so disposed that it is uncovered by Specification of Letters Patent.

Application filed. November 8, 1986. Serial. No. 3a2 i89.

.lEsp-eeially is- Vl'hen the lower end of this pas- Patent-ed. Tune 23, was.

and is placed in a line about midway between the two ends ol the duct or passage in the cylinder. in zwcoinplishing this result, i employ several novel features and combinations, which will he more. fully described hereinafter and particularly pointed out in the claims.

in the accompanying drawings, Figure (1) is a vertical cross-sectional view of a motor equipped with my invent-ilm, the piston occupying the position immediately prior to the. explosion of the charge, and Fig. (2) is a similar view showing the position of the piston at the lowest "point of its working stroke.

(A) is a cylinder of any approved construction and orovidcd with a closed crank case (1), a hollow piston (2) reciprocating in the cylinder being connected by means of a piston red (3) with a crank shaft (4). The head of the piston may be provided with a deflector (5) and the shell of the piston is equipped. with an aperture (6) adapted to register with the lower port (7) of a U-shaped mixture passage (a) conveniently formed in the cylinder wall, or otherwise as preferred. This aperture (6) fully registers with the lower port (7) only when the piston has attained its outward limit of moven'ient inits working stroke, at which time the upper port (9) of said. mixture passage is in free communication with the cylinder and opposite the deflector. (5), to admit-the charge to the cylinder. The return stroke of the piston then compresses the charge which is fired and the piston makes another working stroke.

The exhaust, orb-(10) is preferably located opposite the in ct port (9) and at a slightly higher level than such inlet port, in order to crmitthe escape of the larger portion of urnod gases'prior to the admission of the new charge. v

The mixture intake port (11) comn1unicates with. the crank casing and is controlled by a suitable checkvalve (12), a spring (13) tending to seat the valve atiall times to close thei oi't, a pin (14') being located in advance of tie valvev to lirnit its inward or opening sage (8) to the cylinder, when the piston has about reached its lowest limit of outward movement. Such an arrangement, however, will permit thelvalve (12) to flutter on its seat when at high speed, without correctly performing its duty and in order to allow the valve to become seated during the idle or compression stroke of the piston and prior to the time when the piston completes such stantially equi-distant fromthe ends of the mixture'passage (8).

The effect and operatlon of this construction is as followsAssuming that the piston has reached the limit of its working stroke and is about to make its inward or compression stroke, the exhaust port (10) will have been uncovered to release the products of combustion or the spent charge and directly thereafter the inlet port (9) will have been uncovered by the further movement of the piston to admit the new charge, the aperture (6) registering with port (7) to permit the compressed mixture to pass through the passage (8) and into the cylinder against the dcilcct'or (5) scavenging the cylinder in the usual manner. I I

On its instroke, the piston will first cover the exhaust port (10) and practically simultaneously therewith, will cover the port (7) to prevent the entrance oi further mixture, the free inlet (16) being covered by the piston from a time shortly after it has started on its working stroke until just before it reaches the limit of its compression stroke. The instroke of the piston will immediately tend to create a vacuum in the crank case which is at once relieved by theopening of theil'ieek valve (12) under atmospheric pr-es:-

sure, permitting the entrance through port (11) into the crank case of a charge from the carburetor (15). As the piston compresses the mixture in the cylinder on its instroke, it will continue to draw in a fresh charge through port (11) until the piston nears the limit of its instroke, when it uncovers the lower end of the passage 8 then the assage 8 is filled, but reduces the pressure in tiie crankcase, and asthe piston reaches the limit of its stroke the free inlet (16) is uncovered and mixture is thereupon admitted through such inlet to'the exclusion ,ol" the intake port (11) for the reason that the vacuum Wlll be relieved by the mixture drawn. from the easiest source, and the l'ree'inlet (16) is not ob structed by a check 01' other valve, consequently the mixture will pass into the motor through inlet (16) and permit the spring (13) to fairly close the port (1]). operation takes place in a fraction of a second when the engine is driven at high-speed.

It will be observed that a combustible Of course, this mixture enters through, both the intake (11) and the inlet (16), thereby insuring a full charge to the crank case and to the cylinder.

Having thus fully disclosed my invention, what I claim as new isv A motor having a cylinder a piston and a closed crank case, the cylinder having a passage with its ends in the cylinder and adaph ed to have its ends alternately uncovered on the limits of movement of the piston, a carburetor having its outlet connected to a pair of pipes, one pipe entering the crank case and having a suction valve. therein, and the second pi pe passing from behind the suction valve to the cylinder and entering the cylinder at a point-approximately in a line equi distant between the ends of the passage in the cylinder, the end of the piston uncovering the outlet of the second pipe only at its upward limit of movement.

In testimony whereof, I aflix my signature in presence of two witnesses.

JAMES 1-1. PIERCE. Witnesses:

RALPH S. WARFIELD, .Gno. B. WILLCoX.

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